buffer-overflow

I was reading this book Art of Exploitation, which is kinda good book and I run across that example from exploit_notesearch.c file. Briefly author tries to overflow program from notesearch.c int main(int argc, char *argv[]) { int userid, printing=1, fd; char searchstring[100]; if(argc > 1) // If there is an arg strcpy(searchstring, argv[1]); else // otherwise, searchstring[0] = 0; The argument of the main function is copied to the searchstring array and if the argument is bigger than 100 bytes it will overflow the return address from the main function. The author prepares the shellcode in

From The GNU C Programming Tutorial : The fgets ("file get string") function is similar to the gets function. This function is deprecated -- that means it is obsolete and it is strongly suggested you do not use it -- because it is dangerous. It is dangerous because if the input data contains a null character, you can't tell. Don't use fgets unless you know the data cannot contain a null. Don't use it to read files edited by the user because, if the user inserts a null character, you should either handle it properly or print a clear error message. Always use getline or getdelim instead of fgets

I have heard about a buffer overflow and I would like to know how to cause one. Can someone show me a small buffer overflow example? New(And what they are used for?) David Dean A buffer overflow is basically when a crafted section (or buffer) of memory is written outside of its intended bounds. If an attacker can manage to make this happen from outside of a program it can cause security problems as it could potentially allow them to manipulate arbitrary memory locations, although many modern operating systems protect against the worst cases of this. While both reading and writing outside of